What is Imagination Learning and Imagination machines?
The whole idea of Imagination Learning seems to be in its infancy. The author of the response you linked wrote a paper on the subject, but as he notes the paper is more of an outline for "a new overarching challenge for AI." The second link you posted is not directly related to the ideas referenced in the paper on Imagination Learning, other than that both use the idea of imagination in humans as inspiration. In short, there does not seem to be much information on this topic and I suspect it will stay that way until we learn some of the underlying processes that go along with imagination in humans and then maybe Imagination Machines may come to fruition.